University of Arkansas, Fayetteville Division of Agriculture


Rice, native starch, chromatography


Starch determines a large proportion of the textural properties of cooked rice. The amylose: amylopectin ratio plays a significant role in the functionality of native starch. In this study a medium-grain rice cultivar, ‘Bengal’, was used for starch structure characterization using high performance size-exclusion chromatography (HPSEC). This cultivar is characterized by having lower amylose content (15% to 20%) than long grain cultivars and being sticky when cooked, similar to short-grain cultivars. Rice samples were harvested in 1999 from five locations around Arkansas at state verification trials where cultural practices are closely monitored. Samples of this cultivar stored at a specified moisture level for a pre-determined period of time were also subjected to texture analysis by means of a Texture Analyzer. The data measured with the HPSEC was related to instrumental texture attributes. Chemical characterization data (carbohydrate profiles) of rice samples were used to predict texture attributes of cooked rice such as hardness and stickiness. Instrumental texture attributes of hardness and stickiness were successfully predicted for Bengal rice from starch-profile data obtained though HPSEC analyses. Both attributes proved to be well predicted, based on their high coefficients of determination of 0.97 and 0.85, respectively. The statistical analysis indicates that starch structure characterization using HPSEC may be related to instrumental measurements of texture attributes.